The present invention relates to an improvement in outside watering troughs for livestock and more particularly for thermally insulated watering troughs which are subject to cold in winter.
It is known to position in the open air or under simple canopies, watering troughs that are thermally insulated and closed at their upper portion by a system using a valve (a ball for example), which is actuated by the animal with his muzzle.
It is thus necessary to empty the watering trough regularly, because the water becomes polluted and if possible to clean it.
To facilitate cleaning, there has been proposed, in the patent EP 0 753 250 in the name of the applicant, to fix the cover of the tank of the watering trough by rapid attachment means; such that one can raise it easily and rapidly without needing tools. But it is necessary to empty it to clean it. For this purpose, there has been disposed adjacent the bottom of the tank an emptying plug, by housing this plug in the sidewall of the tank, so as to avoid having it damaged by the hoofs of the animals.
In spite of these improvements, the emptying and cleaning of the tank still gives rise to problems to which the present invention provides a satisfactory solution.